The recent proliferation of inexpensive computer processors has influenced games and toys. Game systems have been built which utilize computers and sensors to detect human interaction with elements of a board game. Some kinds of toys and games use embedded sensors in conjunction with control logic to increase the level of interaction by the players.
Many conventional stand-alone computer games provide a visual display of game activity through an electronic display system such as a pixilated flat panel display. Such displays lack a three-dimensional character, and obviate physical interaction between the player and tangible playing pieces, characteristics that are inherent in typical board-based games. One common feature of conventional board games is the use of one or more movable playing piece integral to the action of the game.
Physical interaction with a game board and game pieces is especially desirable for children's games. The interaction with the board and game pieces enhances the experience and more effectively brings the children into the game. Some games utilize player response or reaction time as a controlling element. An example of such a game is a quiz game where two or more players compete to answer a question, and the first player to respond after a question is asked gets the first opportunity to answer the question correctly and thereby gain points and advance in the score ranking. Yet another example is a game using a thrown die to control a decision point in the game flow, such as determining how many spaces a player will move his or her game piece.
Capacitive sensors are known. Generally such sensors use conductive plates placed in proximity to each other, such that proximity to some other object alters the capacitive coupling of the plates to one another and to ground. However, the geometry of the capacitive sensor, and the mode of use, are both critical in determining the utility of specific applications. The optimum geometry and mode of operation are not obvious from the theory of operation, and the development of reliable, low cost, multifunction capacitive sensor systems for game boards has required a great deal of experimentation and trial and error.
A typical capacitive touch sensor relies on the sheer size of the human body, and therefore the large capacitance between the human body and ground, which a board game piece lacks. There is significant capacitance between a person's body and the system ground simply because of the body's surface area. Game pieces have a much smaller surface area, and it was found in testing that a touch sensor using a single conductive pad is not effective at detecting a game piece.
In order to detect a game piece using capacitive sensing, placing the game piece on the game board over a sensor must cause a significant increase in capacitance between the sensor and ground. In order for this to occur, the sensors and game pieces must be designed to provide good capacitive coupling between the sensor pad and the game piece, and between the game piece and ground, when the game piece is placed on one of the sensor locations on a game board. Referring to FIG. 1, a simple circuit model for detection of a conductive object—either a game piece or the touch of a player—using a capacitive sensor is shown. The sensor has a capacitance to ground of CSG. When a conductive object is placed in proximity to the sensor, and a person touches the object, the capacitance of sensor to ground CSG increases to match the capacitance of sensor to person COS in series with object to ground COG. In a typical touch sensor application, no special provision is necessary for providing for capacitance between the user and ground—the large size of the person's body provides adequate capacitive coupling to ground. However, in order to reliably detect smaller items, such as board game pieces, the detection system must ensure effective object-to-sensor and object-to-ground capacitive coupling sensor, COS and COG respectively, in order to drive a large enough change in sensor-to-ground capacitance for detection and identification, where applicable. Referring to FIG. 2, a modified circuit is shown.
Thus, there is a need for an interactive game system using capacitive game piece and touch sensors that: (1) reliably detects game pieces when placed on a game board location; (2) reliably detects player touches on the game board; (3) reliably detects player touches on the game pieces; and, (4) reliably identifies individual game pieces.
Presently known art attempts to address this problem, but has not completely solved the problem. The following represents a list of known related art:
Date ofReference:Issued to:Issue/Publication:U.S. Pat. No. 5,082,286Ryan et alJan. 21, 1992U.S. Pat. No. 5,129,654BognerJul. 14, 1992U.S. Pat. No. 5,853,327GilboaDec. 29, 1998U.S. Pat. No. 6,168,158BulsinkJan. 02, 2001U.S. Pat. No. 5,188,368RyanMay 16, 1991U.S. Pat. No. 6,955,603Jeffway et alAug. 01, 2002
The teachings of each of the above-listed citations (which do not itself incorporate essential material by reference) are herein incorporated by reference. None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention.
U.S. Pat. No. 5,853,327 “Computerized game board” describes a system that automatically senses the position of toy figures relative to a game board and thereby supplies input to a computerized game system. The system requires that each game piece to be sensed incorporate a transponder, which receives an excitatory electromagnetic signal from a signal generator and produces a response signal which is detected by one or more sensors embedded in the game board. The complexity and cost of such a system makes it impractical for low-cost games and toys. Light emitter/sensor systems are also easily interfered with by players, dust and other objects, which can be especially frustrating with very young players who tend to be messy.
U.S. Pat. No. 5,082,286 “Sensory games”, U.S. Pat. No. 5,129,654 “Electronic game apparatus”, U.S. Pat. No. 5,188,368 “Electronic game apparatus”, and U.S. Pat. No. 6,168,158 “Device for detecting playing pieces on a board” all describe systems using resonance frequency sensing to determine the position and/or identity of a game piece. Each of these systems requires a resonator circuit coupled with some particular feature of each unique game piece, which increases the complexity and cost of the system while reducing the flexibility of use.
Another approach to sensing player interaction is described in U.S. Pat. No. 6,955,603 “Interactive gaming device capable of perceiving user movement”, which uses a series of light emitters and light detectors to measure the intensity of light reflected from a player's hand or other body part. Such a system requires expensive light emitters and light detectors, the number and spacing of which determines the spatial sensitivity for detection.